Similar to the "Open all bags with auction house" option.
(Would love to see the above option applied to opening a bank/gbank as well)

Sometimes I accidentally close the bankui, either misclicking when closing my bank or just simply not paying enough attention.

I personally never ever want the bankui closed if I'm actually viewing it. Currently, if you close it, it will stay closed until you run the command again. An option toggle to make it always appear when opening a bank/gbank would be great.